2 * RTP JPEG-compressed video Packetizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavcodec/bytestream.h"
23 #include "libavcodec/mjpeg.h"
24 #include "libavutil/intreadwrite.h"
27 void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
29 RTPMuxContext *s = s1->priv_data;
30 const uint8_t *qtables = NULL;
32 uint8_t type = 1; /* default pixel format is AV_PIX_FMT_YUVJ420P */
35 int off = 0; /* fragment offset of the current JPEG frame */
40 s->timestamp = s->cur_timestamp;
42 /* convert video pixel dimensions from pixels to blocks */
43 w = s1->streams[0]->codec->width >> 3;
44 h = s1->streams[0]->codec->height >> 3;
46 /* check if pixel format is not the normal 420 case */
47 if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ422P) {
49 } else if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ420P) {
52 av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
56 /* preparse the header for getting some infos */
57 for (i = 0; i < size; i++) {
61 if (buf[i + 1] == DQT) {
63 av_log(s1, AV_LOG_WARNING,
64 "Only 8-bit precision is supported.\n");
66 /* a quantization table is 64 bytes long */
67 nb_qtables = AV_RB16(&buf[i + 2]) / 65;
68 if (i + 4 + nb_qtables * 65 > size) {
69 av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
73 qtables = &buf[i + 4];
74 } else if (buf[i + 1] == SOF0) {
75 if (buf[i + 14] != 17 || buf[i + 17] != 17) {
76 av_log(s1, AV_LOG_ERROR,
77 "Only 1x1 chroma blocks are supported. Aborted!\n");
80 } else if (buf[i + 1] == SOS) {
81 /* SOS is last marker in the header */
82 i += AV_RB16(&buf[i + 2]) + 2;
87 /* skip JPEG header */
91 for (i = size - 2; i >= 0; i--) {
92 if (buf[i] == 0xff && buf[i + 1] == EOI) {
93 /* Remove the EOI marker */
103 if (off == 0 && nb_qtables)
104 hdr_size += 4 + 64 * nb_qtables;
106 /* payload max in one packet */
107 len = FFMIN(size, s->max_payload_size - hdr_size);
109 /* set main header */
110 bytestream_put_byte(&p, 0);
111 bytestream_put_be24(&p, off);
112 bytestream_put_byte(&p, type);
113 bytestream_put_byte(&p, 255);
114 bytestream_put_byte(&p, w);
115 bytestream_put_byte(&p, h);
117 if (off == 0 && nb_qtables) {
118 /* set quantization tables header */
119 bytestream_put_byte(&p, 0);
120 bytestream_put_byte(&p, 0);
121 bytestream_put_be16(&p, 64 * nb_qtables);
123 for (i = 0; i < nb_qtables; i++)
124 bytestream_put_buffer(&p, &qtables[65 * i + 1], 64);
127 /* copy payload data */
130 /* marker bit is last packet in frame */
131 ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);